This invention relates to apparatuses and methods of editing video data coded according to MPEG (Moving Picture Experts Group) standard.
Shown in FIG. 1 is a method of editing MPEG video data coded by intraframe coding and interframe predictive coding to splice two bit streams of the MPEG video data of sequential GOPs (Group of Pictures).
The method shown in FIG. 1 is to remove GOPs A4 to B3 and splice bit streams of GOPs A3 and B4, so that continuance is achieved in view of GOP. However, the same value of VBV (Video Buffering Verifier) must be set for the GOPs to achieve continuance in view of VBV. Furthermore, the edition shown in FIG. 1 requires re-encoding to have the same VBV delay for GOPs or closed GOPs in which amount of coded data is constant for each GOP for achieving continuance of VBV delay. This method is thus not capable of splicing bit streams in the midway of a GOP.
Such a method capable of editing bit streams in the midway of a GOP is shown in FIG. 2. Shown in FIG. 2 is to remove bit streams from in the midway of a GOP A4 to the other midway of a GOP B3. The GOPs A4 and B3 each being split into two due to edition are decoded and coded again to form a GOP C.
This method has a drawback, that is, it causes deterioration of decoded pictures corresponding to re-encoded frames due to restriction on amount of codes for frames to be subjected to re-encoding.
In detail splicing two MPEG video data coded by interframe predictive coding, that is, just connecting two data frame by frame, causes pictures to go fuzzy. Furthermore, no continuance of VBV delay on the point of connection (edition) of video data causes overflow or underflow at a decoder input buffer, thus resulting in pictures going fuzzy or a halt on moving pictures. This would happen because the decoder input buffer compensates for variation of data amount per frame of input coded data.